let i='星期一';
let j=`今天是：${i}`;
console.log(j);//今天是：星期一

let arr=[12,'456','asd'];
arr[1]='小小';

let obj={
    name:'小不点',
    age:20,
    sex:'男'
};
console.log(obj.name); //小不点
console.log(obj); //{ name: '小不点', age: 20, sex: '男' }

let num='name';
let myObj={
    [num]:'小艾',
    ['a'+'ge']:18
};
console.log(myObj[num]); //小艾
console.log(myObj);//{ name: '小艾', age: 18 }

// 自动生产一个值
let welcome =Symbol();
let myObj1={};
myObj1[welcome]='欢迎光临';
console.log(myObj1[welcome]); //欢迎光临

